A switch of one type is disposed around the driver's seat of an automobile, while other types of switches are disposed around other seats for controlling the power windows of an automobile. For example, as a safety consideration, the switch around the driver's seat may be used to drive a motor forward or in reverse for opening and closing a window, whereas those around the othe seats may drive the motor in only one direction to close a window. Generally, the switch around the driver's seat is required to have its terminals for energization connected together, so that the switch can control a forward driving circuit and a reverse driving circuit, while the terminals of switches around the other seats should be disconnected from each other so that the switch can control only one driving circuit. The simplest countermeasure heretofore taken to form such circuitry has been to modify the switch configuration. When this conventional method is employed, it is necessary that switches of different configurations be manufactured independently for use with the power windows of an automobile.